A Certain Occult Connection
by Panzer4life
Summary: When an assignment shows the Ruiko isn't related to who she believed to be her parents, she get dragged into the supernatural world, one where things that go bump in the dark really exists. How will she react to her true parentage, a world war that has been in the making for decades, and the various factions vying for control? Rated M for violence, language, and future lemons.


**Disclaimer: I don't own 'A Certain Magical Index', 'A Certain Scientific Railgun', nor 'Hellsing Ultimate'. They are property of their own respective owners.**

 **A/N: This chapter is updated, and thus the rewrite has begun! Please after reading the chapter read the A/N at the end to see what route the story is taking.**

* * *

 _Ark 1: Revelations_

 _Chapter One: First Revelation_

* * *

 _~Academy City, Japan~_

"Today we will be discussing genetic heritage, and how certain traits can be determined using the traits observable in those that came before," said Mr. Daigo, the teacher of Class D-1 of Sakugawa Middle School. Most of the students groaned, as it didn't have anything to do with Esper development, but a few remained quiet.

Towards the back of the classroom sat Saten Ruiko. She was 13, with long black hair, blue eyes, and on par for the height for her age, Saten Ruiko was an optimistic person. She had come to Academy City when she was nine to fulfill her desire to have powers like all the Espers that begun to appear on TV. However, four years later and she still lacked any powers, being a ranked 0 and not even being considered an Esper. It had frustrated her, but she buried it as best she could with apathy and having a few close friends.

Friends such as her desk neighbor Uiharu Kazari, a low Level 1 Esper with the ability Thermal Hands. She and Uiharu got along together very well, except of course when Ruiko lifts her skirts and comments on Uiharu's choice of panties. But despite those times, they were the best of friends, and as such Ruiko could look past her lack of an ability.

Still, Ruiko often wondered what her ability would be if or when she got to Leveling up. She liked the idea of being able to manipulate metal, no, electricity! Seriously, she would never need to worry about losing a charge on her cell phone, she wouldn't have to worry about getting zapped again, and so many other possibilities she couldn't fully comprehend them.

That said, Ruiko was brought out of her day dreaming when Mr. Daigo had stopped talking about the basics of genetic heritage and started on giving them their instructions for their assignment.

"Your assignment will be to determine what traits you inherited from your parents using what we discussed in class today. You will have a week to fill out worksheet, and be certain to show all your work," Mr. Daigo instructed. The bell rang, thus ending class for the day. "And remember everyone, next week is the SYSTEM Scan, so do practice in trying to unlock your personal reality or improving your ability as the case may be."

As the classroom began to empty, Ruiko internally panicking. She is freaking, having zoned out during the lesson and thus didn't know how to complete the assignment, which meant she would have to study by herself. She groaned; she had wanted to look up the latest rumors and urban legends on the internet!

"Ms. Saten," came Mr. Daigo's voice. Ruiko whipped her head to her teacher. He smiled, extending a piece of paper to her. "I noticed you had been zoning out during class, so here are some notes you can use to be able to complete your assignment. Just next time, please do pay attention."

"Ehehe, I will sensei," Ruiko promised. She took the notes and put them in her bag. Nodding to her teacher apologetically, Ruiko made her way out of the classroom, planning on heading to her dorm so she could knock out the assignment and review the notes so she got it done correctly.

It didn't take her long to reach her dorm, as thankfully the dorms were located close by to the school, and as usual, Uiharu was out, probably doing her time at the 177th Judgement Branch. Ruiko sighed as she put on some music as she got the notes out.

The notes appeared to be premade with the purpose of touching on the basic of genetics and inherent traits, probably because others like her didn't pay attention or didn't understand the lesson. But none the less, Ruiko was glad for it, quickly reviewing the notes.

In basics, a trait could be determined in an offspring by seeing what traits the parents had, and using a chart to determine the likelihood of the trait appearing in the offspring. The most basic example was a Punnett square as described by Gregor Mendel. In layman's term, the father's and mother's genes, as determined by their parents, would make a chart, with varying possibilities depending on the gene's nature of being either dominant or recessive. If for example each parent had both a recessive and a dominant gene for a trait, then there was a 75% of the dominant trait being the gene selected while only a 25% chance for the recessive trait being chosen.

However, unlike the Punnett Square most were used to, most distinguishable traits that one can identify themselves with, such as hair color and eye color, were polygenetic, or being determined from multiple genes and not one gene. Thus, Ruiko's work was a lot more difficult for her to work on. Still, thankfully Mr. Daigo had given her the basics to determine such traits, all she needed to do was contact her family for the relevant information.

Ruiko grabbed her phone, hesitating to call her mother. While she liked to think that her family cared for her greatly, they as of late hadn't been so close. Perhaps the lack of direct interaction was to blame, but it seemed with each passing month her mother, father, and brother drifted farther away from her, with less calls, less and shorter letters, and they hadn't come to Academy City last year. She sighed, perhaps she was thinking too much into it.

Dialing the number for her mother's cell phone, Ruiko waited three rings before the line was connected.

"Hello, this is Mrs. Saten, who is this?" the voice of her mother came through, with a very soft-spoken voice that Saten Ruiko knew her mother had.

"Hey Mom, it's me, Ruiko," Ruiko said. She heard her mother gasp in surprise.

"Oh Ruiko, it's good to hear from you!" her mother said. "So how are you doing, is school going okay?"

"I'm fine mom," Ruiko replied. "Although I could use your help?"

"Um, what do you need sweetie?" her mom asked. Ruiko paused; her mother never called her sweetie except to embarrass her in public. Shaking her head of wondering why her mom called her sweetie, Ruiko went to the subject of her call.

"I got a class assignment of hereditary traits, so I could use color photos of you, dad, and both of your grandparents," Ruiko said. "And I only have a week to complete this assignment, so could you please be quick with gathering the photos and sending them to me?" She heard her mother rubbing her chin; again, this was something that Ruiko couldn't recall her mother doing.

"Um, I take it the assignment is mandatory?" her mother asked. Ruiko raised her eyebrow in confusion. Why was her mother acting out of character? Had four years changed her mother's behavior? And why was her mother wondering if this assignment was mandatory; her mother had reinforced into her to complete all classwork given to her, even optional assignments.

"As far as I know, yes," Ruiko said. "Is something wrong mom?"

"Oh no, nothing is wrong Ruiko, just…well it might be hard to get ahold of color photos of your grandparents, but I can be sure to send you color photos of your dad and I in three days. Um, was there anything you needed?"

"Well, not really, but if you have…" Ruiko wasn't able to finish her statement as the phone line went dead. Ruiko stared into the wall, her phone still pressed into her ear. Her own mother hung up on her? What the hell had happened in four years?! Her mother would never have hung up on her! Ruiko closed her cell phone, as she felt her throat tighten as she tried to resist the urge to cry. Her own mother hung up on her, why?

Ruiko went to her bed and laid down, wondering that question as she eventually gave in and cried herself to sleep. Her sleep would be fitful and full of nagging doubts about whether her time in Academy City was worth the growing distance between her family. When she awoke, she would be no closer to that answer than when she fell asleep, but she felt as though things were going to change.

* * *

Three days had passed, and like her mother promised, Ruiko had copies of her mother, father, and her mother's parent's photos. Apparently, no color photos of her father's parent's, who had died before Ruiko been born, could be found, but Ruiko was certain that it wouldn't be to detrimental to her assignment. It was after school, and Uiharu was working at Judgment as per the usual, leaving her to do the assignment finally.

She began by hitting the rather obvious ones first, such as her skin tone, which was mostly from her mother, and her hair color, which both her mother and father had black hair. Continuing onwards, Ruiko had gone through halfway through the worksheet when she got to the one she thought would be the easiest to figure out; eye color.

Her mother had brown eyes, which seemed to be on course as her grandparents also had brown eyes. Her father meanwhile had complete heterochromia, with brown and green eyes. Ruiko pulled out a mirror to look at what color her eyes were, only to frown at the color they were; blue eyes. Sure they weren't as blue as the sea, but they were undeniably blue. Looking over the notes Mr. Daigo gave her, Ruiko read the section detailing eye color.

 _Of the various eye colors, brown eyes are considered dominant in most of the world, and in some parts of the world are the only iris color in the population. It is common in those whose heritage are from Asia, Africa, the Americas, Oceania, Eastern and Southern Europe._

 _Blue eyes meanwhile are significantly rarer, thus being considered a recessive trait in general despite eye color being a polygenetic trait. They are common in Northern and Eastern Europe, although they also appear in North Africa, Central Asia, South Asia, and West Africa._

Ruiko had stopped, looking at the accompanying chart that would allow her to figure out the odds of her having blue eyes. She quickly created a Punnett square (as while it may be polygenetic, Mr. Daigo had explained the day after that he wasn't going to have his students struggle through finding out their exact genetic make up to figure out their traits), listing her mother as having 'BB' (the capital B signifying Brown eye related-traits), while her father she listed as 'Bg' (lower case g for Green eyes).

Filling out the chart went quickly, but as she compiled it, Ruiko felt a cold sinking feeling take hold in her chest. See, if her parents had been carriers of blue eye genes, then even if they had brown eyes, she could have a 25% chance of having blue eyes. But her parents didn't even have the necessary traits for blue eyes; her mother had parents with Brown eyes, and if her father's case of heterochromia wasn't related to environmental exposure, his parents had Brown and Green eyes. Under no circumstances should Ruiko have blue eyes, unless…

Ruiko stared at the chart in front of her as if it was a letter of disownment from her family. She couldn't have blue eyes, unless she wasn't blood related. But Ruiko wouldn't believe it; she had seen pictures of herself as a baby in her mother's arms! She had grown up with her family for years, and they had always…Ruiko frowned, thinking how off her mother had been when she called. Did she fear that Ruiko would find out-damn it, now isn't the time to have doubts!

Ruiko growled, wondering what she should do. The only thing that would ease her mind was to have her DNA checked against her parents to make sure they were her parents. She knew that Academy City would have access to the medical files of her parents in the event something happened to her, so it wasn't too unreasonable to think she could get her DNA checked.

But should she? It would mean that she had no trust in her mother and her father, saying that she couldn't even believe they were related. But at the same time, her assignment has given her more than damning insight that may be the case. Ruiko closed her eyes before deciding she would head to the hospital to get her DNA checked. She sighed; hopefully she was over-reacting.

* * *

"Hey Saten, what's wrong?" Ruiko turned and saw it was her best friend Uiharu. The young, black haired, brown eyed girl with a flower band in her hair was so nice, hardly ever holding a grudge against anyone. And sadly she had to notice her downed demeanor.

"It's nothing to worry about Uiharu," Ruiko lied, not wanting to depress her friend unnecessarily. But she had a bit on her mind.

Ruiko had turned her assignment in to Mr. Daigo, and was waiting for the results of the DNA test to see if her parents were really her parents. She really hoped she was being paranoid, and was mistaken about her assumption, but she couldn't shake off the feeling it was the truth.

"Well, I'm going to head over to do work for Judgement, so don't wait up for me!" Uiharu cheerfully replied. Ruiko nodded numbly.

"Yeah, okay then, have fun," Ruiko replied quietly. Uiharu paused, thinking to double check on her friend, but decided that if her friend was really troubled, she would've said something already.

"Okay Saten, take care and I'll see you later," Uiharu said before she left. Ruiko remained seated at the bench she had been sitting at, numbly waiting for a message from the hospital to tell her the results of the test. However, as she waited, she heard a scream.

"The hell?" Ruiko questioned, turning to the source of the scream. It was down an alleyway. She would've called for help, but her phone never got reception here near the school. "Screw it, I'm not going to stand by and hear later that someone died."

Ruiko sprinted into the alleyway, following the source of the scream, which turned to following whimpers and groaning. Ruiko felt foolish, chasing the noise of a person in distress, but she couldn't see herself not doing something, anything to help. She took a left, only to see a sight which she wished she never saw.

A school girl wearing her school uniform was being held up by a tall teen wearing a beanie and a white beater by one hand. Ruiko saw the blood flowing down onto the teen's hands, and he had a shark like smile.

"Ah, these bitches are so easy to kill, shame this one's dead," the teen said, before pausing, as though hearing something. Ruiko was paralyzed as the teen turned his head towards her. "Oh, another lamb came to the slaughter eh? What fun I get to have today!"

The teen squeezed the girl's neck until a very audible snap was heard, then dropped the corpse to the ground. Ruiko did the only thing she knew to do, and that was to run.

Turning around, Ruiko only made it three feet before feeling a hand holding her in place on her shoulder.

"Thought you could run little lamb?" the teen asked rhetorically, lower his face next to her. "Now that I have you, I'll have so much-"

Ruiko panicked, turning around and slugging the teen in the face, only to be horrified that her punch did little to him. In fact, the teen found is amusing.

"Oh ho, what fun, this little kitten has claws!" he shouted. He grabbed Ruiko by her arm and flung her over his shoulder and into the corpse. "But it won't do you any fucking good bitch!"

Ruiko slammed face first into the corpse, feeling her jaw crack, and more than one of her teeth shattered. She groaned in pain, before looking at her hand. It was scrapped, but the most noticeable detail was the blood that now covered it. She was momentarily mesmerized by it, but the voice of the teen dragged her back to reality.

"Oh, I'm going to have so much fun raping your corpse until not even your family will be able to recognize you!" the teen shouted. "I'm first going to break your fingers, your arms, then move to your legs and break them. Then I'll-what are you doing?!"

Ruiko was shocked, finding her blood covered fingers were in her mouth, sucking on them like a kid would a popsicle. _It tastes like cream soda with a bit of iron_ , Ruiko mused before the disgust of her actions kicked in. _Oh my god, I tasted someone's blood! What the hell is wrong with me?!_

The teen, knowing what was going on, ferally growled. How dare someone else get on his fucking turf?! He lunged forward, rearing his arm back, planning on decapitating the bitch in front of him, only to be shocked when she casually knocked away his arm.

Ruiko was shocked as well, not expecting to be able to do anything to him, but instead she matched his strike with her block. She grinned, perhaps it wouldn't be the day of her death after all!

The teen's eyes widen as he saw the bitch's eyes turn from blue to violet, and he noticed one subtle change that she probably didn't notice; her canine teeth had sharpened and lengthened. _Shit, I've fucked up_ , the teen thought, remembering the one condition that applied when he met that fedora wearing dandy man a few nights ago.

" _And remember, don't attack this girl," the man with the fedora said, showing the teen a picture of the bitch in front of him. "One of my colleague would be most displeased if anything happened to her."_

The teen barely reacted as Ruiko punched him in the gut, sending him back. He snarled in pain; he was supposed to be fucking immortal, not the weak piece of shit Level 0 that this damned city insisted he was! He decided to take his chances and kill this bitch; perhaps he would be lucky and evade the fedora man's colleague.

He roared as he charged forward, throwing a punch of his own, only to be again countered by a side swipe from Ruiko, who returned the favor and slammed her first into the teen's face, cracking his nose. The teen snarled as he fell to the ground, glaring at her.

"I swear I'll fucking kill you!" the teen vowed, before running out of the alley way.

Ruiko stood in place, her violet eyes shifting back to her normal blue, before collapsing. She felt exhausted, tired, and why the hell did the sun seem so oppressive now? Ruiko curled up, closing her eyes, not noticing the sound of approaching footsteps coming from behind.

* * *

Ruiko opened her eyes, before closing them. The damned sun was in her eyes again! _Wait, why am I comfortable?_ Ruiko quickly noticed she was in a hospital bed, thankfully still in her clothes.

"Oh you're awake!" Ruiko couldn't brace herself in time for the bear hug that Uiharu was giving her. "I was so worried that you were hurt badly, considering they found Asura-san dead in the same alley they found you!"

Ruiko felt confused; Asura-san, why- then it clicked. The alleyway, the deranged teen, and her tasting blood. She shuddered, before she turned her attention to Uiharu, who apparently brought someone with her.

"Uiharu, why are you here, why am I here, and who is that?" Ruiko asked. Uiharu frowned.

"Well, we had a case of burglary, and we were escorting someone who was injured when the perp tried to get away, and then you were being carted in, knocked out," Uiharu began. "You apparently had fallen unconscious from exhaustion, and you had a broken jaw and a few lost teeth. We stayed until you finally awoke, so its five in the evening."

"Okay, so who is she though?" Ruiko asked, checking her jaw. It was tender, but didn't feel broken. Perhaps medical tech in Academy City was simply that good. Uiharu beamed.

"This is Kuroko Shirai, my partner at Judgement," Uiharu answered.

Ruiko looked at Kuroko. Kuroko had her long auburn hair in a twin tail style, wearing if Ruiko wasn't wrong a Tokiwodai uniform, with a Judgement Band around her right arm. She seemed to exude an aura of seriousness about her, like Kuroko really need to relax. Ruiko's analysis of Kuroko was interrupted when the door opened, revealing a doctor whose face resembled a frog.

"Ah, Ms. Saten, good to see you are awake," the doctor said, before turning to the others in the room. "If you could wait outside while I speak with Ms. Saten, that would be appreciated." Uiharu and Kuroko, leaving the doctor and Ruiko remaining in the room.

"I must say, I've never had a patient heal quite so fast before," the doctor began. "But that isn't the reason I asked your friends to leave the room; I've the results of your DNA test."

Ruiko swallowed; this was it, when the truth would be revealed, for better or for worst.

"And what are they?" Ruiko asked quietly. The doctor sighed.

"In short, the tests came back negative; Mr. and Mrs. Saten are not your parents by blood," the doctor replied. Ruiko felt thunderstruck by the realization. Her fears were confirmed; she wasn't related by blood to the people she had known as parents, and that was why they had distanced themselves from her.

"Considering this, I checked the tests to determine where your blood parents' origins would be, and it came back to Central and Northern Europe, but beyond that I don't know," the doctor explained. "I'm sorry you had to find out this way."

"I guess it doesn't matter how I found out now does it?" Ruiko said bitterly. She sighed. "Thank you, doctor, but if you could leave, I'd appreciate that." The doctor nodded, leaving the room. Ruiko leaned back and looked out the window, seeing the sun setting. She felt tears rolling down her cheeks, her mind occupied on one thought; _who are my parents?_

* * *

The teen was snarling as he headed through the alleyways back to his safe house, furious over letting that bitch live. Considering this was Academy City, she would inform Judgment and Anti-Skill about his looks, and then they would be hunting his ass down. He however knew he had the abilities that the man had given him, and they would be more than a match against the ants of this city!

He smirked as he saw his safe house in front of him, only to frown when he heard something.

"What the hell is it…wait, is it singing?" the teen questioned. He listened, confused as it wasn't in Japanese, but something that sounded European.

" _Mein Sohn, nur Mut_

 _wer Gott vertraut baut gut_

 _Jetzt auf, in Bergen und Klüften_

 _tobt morgen der freudige Krieg_

 _Das Wild in Fluren und Triften_

 _der Aar in Wolken und Lüften_

 _Ist unser und unser der Sieg!_

 _Und unser der Sieg!_

 _Und unser der Sieg!"_

The teen found the source of the singing, and was puzzled. It was a tall and lanky woman, with long blue hair, glasses over blue eyes and freckles, and she seemed to be holding something on her shoulder.

"Oi bitch, minding taking your singing elsewhere?" the teen snarked. The woman stopped, looking at him seriously.

"Oh, apologies sir, but you see I vas looking for you tonight," the woman replied. The teen narrowed his eyes.

"And what exactly would you want with me?" the teen demanded, getting into a fighting stance. The woman smiled, but it wasn't one of happiness. No, it was maniacal and promised pain and suffering for ages on end.

"I assume you know my colleague Tubalcain Alhambra, the one who introduce you to the doctor who gave you the gifts in exchange for causing bloodshed and carnage?" The woman asked. The teen's eyes widen, realizing this was the person the fedora man warned him about. He tried to charge.

The woman wickedly grinned as she gripped her rifle and extended it in front of her, firing a shot. She guided it into the teen's legs, stopping him in his track, before looping around to circle numerous times to shatter each and every ribcage one by one. She smiled as the teen screamed in pain. She then directs the bullet to slowly move through the teen's brain through his eye, to extend his death as painfully as possible.

She lowers her rifle when the teen's body lays on the ground unmoving and slowly pouring blood onto cold concrete. She wipes her glasses with the hem of her shirt, musing as how pathetic this wannabe vampire was. Compared to her, he was not even an ant. And compared to those she knew, he wouldn't even be a speck of dust.

"Guten Abend Rip Van Winkle," came a young voice from behind. Turning around she smiles at one of her colleagues.

"Guten abend auch, Schrodinger," Rip said. The werekin was in his Nazis youth uniform, and his cat ears were exposed for all the world to see.

"I take it you took care of the problem?" Schrodinger asked. Rip nodded.

"Ja, meine tochter is safe from a pathetic excuse of a vampire," Rip casually said. She paused for a moment, thinking about something. "Schrodinger, do you think I should meet meine tocther? Because I know that she now knows that those human are not her parents."

"Ah, vell perhaps, but it would mark her for our enemies," Schrodinger pointed out. "Hey, what about her vater? It wouldn't be too hard to cause a case that drags Hellsing here; cause trouble for the Amakusa church, which travels up to the Church of England and then it's just a matter for Hellsing to come here. I would inform her vater about her and what she looks like; perhaps he could teach her how to protect herself."

Rip smiled, thankful for Schrodinger's helpful suggestion.

"I think I shall," Rip comments. "So let's go, I want to be able to pen a letter before the night is over and the Major loves his reports." Schrodinger nodded.

"That he does."

* * *

 **Author's Notes (Updated): Hoo boy, this rewrite is underway! And what better way to start then by saying what the poll results were. Taken into account for some reader reviews, the winner was…Hellsing!**

 **So the path has been set with the Hellsing option. So expect the upcoming chapters to build up Ruiko's character, including her dhampir nature and powers, along with some build-up. Do note however that Hellsing is a way's away; I planned on introducing Ruiko to Hellsing during the Deep Blood Arc, and that's a couple of weeks away from the start of this chapter, which is before the canon start of 'A certain Scientific Railgun'.**

 **That aside, a few issues I want to address before hand that were brought up in reviews before this rewrite. So let's go through them quickly.**

 **-Touma's eyes: This was a point of contention when people had issues with the 'blue eyes' plot device I used to explain Ruiko's parentage in this fan-fic. The reason being, Touma as blue eyes as well, so doesn't that puncture your point completely? Well not totally; Touma does have blue eyes, a fact I did forget about, but his father also has blue eyes. And so perhaps it stands to reason that one of Touma's fraternal grandparents has blue eyes. Not saying this is true, but it's a possibility.**

 **-Too many OCs: Yeah, not going to joke, but I added too many OCs willy nilly last time, which I am aiming not to do this time. Heck, if all goes to plan, I won't be adding any OCs except 1 this time, except for maybe freak vampires like the one that appeared in this chapter to give Ruiko 'moving targets'.**

 **-Himegami and Deep Blood: Many thought that I was writing off the dangers of Deep Blood, and so this time I intent to give a fully fleshed out reason why it won't be dangerous to Ruiko, Alucard, or any of Millenium's Vampires.**

 **Finally, one last thing before I sign out; Alucard won't be a concern for Aleister Crowley; seriously that guy is fucking broken. Until next time guys, please read, review, follow and favorite, and I'll catch you guys next time.**

 **PS: I almost forgot, you might be wondering why there is only this chapter, well I decided to give you guys this chapter now rather than wait, so please be patient with me, I will try to get them out but I do have other stories that need updating and a rather nasty case of story ideas.**


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